Method for manufacturing microlens and method for manufacturing organic electroluminescence element

ABSTRACT

A method for manufacturing an organic thin film element that includes an organic thin film between a pair of thin film electrodes and at least one electrode being a transparent electrode includes forming a transparent electrode by spraying a material liquid containing a transparent electrode formation material on a base material, and forming an organic thin film on the transparent electrode. This method allows for the manufacture of the organic thin film element by which an organic thin film element with high light-extraction efficiency is simply provided. A method for manufacturing an electro-optic device and a method for manufacturing electronic equipment that utilize the method for manufacturing an organic thin film element are described.

This application claims the benefit of Japanese Patent Application No.2004-203923filed Jul. 9, 2004. The entire disclosure of the priorapplication is hereby incorporated by reference herein in its entirety.

BACKGROUND

The exemplary embodiments relate to a method for manufacturing amicrolens and a method for manufacturing an organic electroluminescenceelement.

An organic electroluminescence element (hereinafter referred to as anorganic EL element), which is a self light-emitting element that itselfemits light by the flow of a current, is excellent in visibility as wellas shock resistance, and has excellent characteristics of low powerconsumption in comparison with an inorganic EL. The organic EL elementis drawing attention as the next generation display device due to theseexcellent characteristics.

The organic EL element typically includes a substrate, an anode, anorganic luminescent layer, and a cathode. In the organic EL element,total reflection occurs at a layer interface due to the refractive indexdifference between materials that constitute layers. The light that isconfined to the layer by the total reflection is propagated in thetransverse direction of the substrate, and then causes edge emitting ornonradiatively disappears in the course of propagation. As a result, theamount of light that emits outside is reduced and the light-extractionefficiency decreases up to about 20%, for example.

To address or solve such a problem, methods of forming prisms andmicrolenses on or around an organic EL element to improve thelight-extraction efficiency are disclosed, for example, in JapaneseUnexamined Patent Publication No. 2003-282255 and Japanese UnexaminedPatent Publication No. 2004-39500.

SUMMARY

In the above patent documents, however, the shape of a mold istransferred to a base material, and therefore microlenses are formed.Accordingly, a mold that is suitable for the design of a device to bemanufactured is required. Other methods for manufacturing a microlens,manufacturing methods utilizing an ink-jet method and a photolithographytechnique are known. However, the ink-jet method has a disadvantage inthat large amounts of microlenses cannot be produced at one time, andthe photolithography technique has a disadvantage, in that the operationsteps become complicated.

Therefore, the present exemplary embodiments provide a manufacturingmethod of a microlens and a manufacturing method of an organic ELelement that permit efficient mass production of microlenses in a simpleway.

To address or solve the above problem, the exemplary embodiments providea method for manufacturing a microlens. The method includes: sprayingand depositing a liquid onto a surface of a base material, the liquidhaving a low affinity to the surface of the base material, the liquidcontaining a material for forming a microlens; and hardening the liquid.

According to this method, the liquid with a low affinity to the surfaceof the base material is sprayed and therefore the liquid becomessubstantially hemispheric on the base material. By hardening thisliquid, a convex microlens can be obtained. Since a microlens is formedby spraying in this way, large amounts of microlenses can be formed atone time by simple processes, enabling the improvement of productionefficiency.

Preferably the base material further has a substrate film that has alower affinity to the liquid than the surface of the base material.Thus, a microlens can be formed regardless of the quality of the basematerial. The substrate film with a lower affinity is preferably alyophobic substrate film.

Preferably the substrate film is formed of a self-assembled monolayer.Thus, a stable substrate film can be formed, and therefore the surfaceof the base material can keep lyophobicity for a long time.

Preferably the average particle diameter of the sprayed liquid is equalto or less than 1 μm. Thus, a minute microlens can be formed.

Preferably the average diameter of the microlens is equal to or lessthan 5 μm. According to the exemplary embodiments, such a minutemicrolens, and further a microlens of, for example, about 0.1 μm can beformed.

Preferably a contact angle between the liquid and the base material orthe substrate film is equal to or more than 50°. Thus, there is atendency that a microlens having a higher focal performance can beformed.

Another aspect of the exemplary embodiments is a method formanufacturing a microlens that includes: forming regions by patterning,the regions being formed with different affinities to the liquid on thebase material; spraying and depositing a liquid onto a surface of thebase material, the liquid containing a material for forming a microlens;and hardening the liquid.

According to this aspect, a microlens can be formed in a desiredposition with excellent accuracy. By adjusting the size of the region inwhich a pattern is to be formed, the size of a microlens can be altered.

Another aspect of the exemplary embodiments is a method formanufacturing a microlens that includes: spraying and depositing aliquid onto a surface of a base material, the liquid having a lowaffinity to the surface of the base material, the liquid containing amaterial for forming an etching protective film such that an etchingfilm having a convex lens shape is formed; and transferring the shape ofthe etching film to the base material by etching the base material onwhich the etching film is formed.

According to this aspect, a microlens is formed by processing a basematerial, and therefore the microlens and the base material areintegrated. Optical loss, or the like, because of the difference inmaterial between the microlens and the base material, does not occur.

Another aspect of the exemplary embodiments is a method formanufacturing an organic EL element that includes: forming a firstelectrode film on a substrate; forming an organic compound layer thatincludes at least a luminescent layer on the first electrode film; andforming a second electrode film on the organic compound layer; amicrolens being formed between any of a plurality of luminescent layersto a light exit surface of the organic EL element or on the light exitsurface using any of the manufacturing methods of a microlens discussedabove.

According to this aspect, the above described manufacturing method of amicrolens can be utilized, and therefore an organic EL element thatcontains a microlens between layers or on the light exit surface andinvolves improved light-extraction efficiency can be manufacturedefficiently in a simple way.

Preferably the refractive index difference between a material forforming the microlens and a material constituting the layer on which themicrolens is formed is equal to or less than 0.05, and further equal toor less than 0.02. Further refractive indices of the material forforming the microlens and the material constituting the layer on whichthe microlens is formed are substantially equal. Thus, the optical lossbecause of the difference in material between the microlens and thelayer on which the microlens is formed can be reduced.

The microlens may be formed on the first electrode film such that theemitted light from the luminescent layer may be collected in thedirection of the light exit surface. The microlens may be formed on thesubstrate such that the emitted light from the luminescent layer iscollected in the direction of the light exit surface. Forming amicrolens between layers or on a substrate in this way permitscollection of the emitted light from the luminescent layer andimprovement of the light-extraction efficiency.

According to the manufacturing method of an organic EL element of theexemplary embodiment, a surface roughness Ra of a layer including themicrolens can be reduced to, for example, 3 nm or less, and ispreferably equal to or less than 1 nm.

Another aspect of the invention is an organic electroluminescence devicecomposed of organic compound layers including a luminescent layerbetween a pair of electrodes, a layer including a group of minutemicrolenses having a surface roughness Ra equal to or less than 3 nm,and preferably equal to or less than 1 nm being located in a positionfrom the luminescent layer to the light exit surface such that theemitted light from the luminescent layer is collected in the directionof the light exit surface.

According to this aspect, since the microlens is formed on a layer in aposition from the luminescent layer to the light exit surface, theoptical loss by the reflection of light in an organic compound layer canbe prevented. The surface roughness Ra of a layer including a group ofmicrolenses (hereinafter, a microlens layer) is equal to or less than apredetermined value, and therefore the film thickness variation amonglayers located on or above the microlens layer is affected by theunevenness of the surface of the microlens layer, and thus can bereduced.

The organic compound layer may include, in addition to the luminescentlayer, a hole transfer layer, an electron injection layer, and otherlayers that are usually included in an organic EL element.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A and 1B are schematics illustrating a method for manufacturingmicrolenses in an exemplary embodiment;

FIGS. 2A and 2B are schematics illustrating an example of microlensesmanufactured by the manufacturing method in an exemplary embodiment;

FIGS. 3A, 3B, and 3C are schematics illustrating another example of amanufacturing method of a microlens in an exemplary embodiment;

FIGS. 4A, 4B, and 4C are schematics illustrating a method formanufacturing a microlens when regions with different affinities arecreated in an exemplary embodiment;

FIGS. 5A, 5B, 5C, and 5D are schematics illustrating another example ofa manufacturing method of a microlens in an exemplary embodiment;

FIGS. 6A, 6B, 6C, and 6D are schematics illustrating an example of themanufacturing method of an organic EL element in an exemplaryembodiment;

FIGS. 7A, 7B, 7C, and 7D are schematics illustrating an example of themanufacturing method of an organic EL element in an exemplaryembodiment;

FIGS. 8A and 8B are schematics illustrating another example of astructure of an organic EL element manufactured by the manufacturingmethod of an organic EL element in an exemplary embodiment;

FIG. 9 is a schematic illustrating an example of an organic EL device inan exemplary embodiment;

FIGS. 10A, 10B, 10C, and 10D are schematics illustrating examples ofvarious types of electronic equipment containing electro-optic devices(such as organic EL display devices) in an exemplary embodiment;

FIGS. 11A and 11B are schematics illustrating examples of various typesof electronic equipment containing electro-optic devices (such asorganic EL display devices) in an exemplary embodiment; and

FIG. 12 is an electron micrograph of a microlens obtained by themanufacturing method of a microlens in an exemplary embodiment.

DETAILED DESCRIPTION OF EMBODIMENTS

A method for manufacturing a microlens according to the exemplaryembodiments will be described below with reference to the drawings.

FIGS. 1A and 1B are views for illustrating the method for manufacturingmicrolenses of the present exemplary embodiment.

A liquid containing a material for forming a microlens is sprayed anddeposited onto a surface of a substrate (base material) 101 shown inFIG. 1A such that a plurality of precursors 102 of microlenses(hereinafter, microlens precursors) is formed.

A method of spraying a liquid containing a material for forming amicrolens is not particularly restricted. From the viewpoint of beingable to form a minute microlens having an average diameter equal to orless than 1 μm, and preferably equal to or less than 0.5 μm, spraying aliquid as a particle having an average diameter equal to or less than 1μm, and preferably equal to or less than 0.5 μm is preferred. Such aspraying method specifically includes, for example, a liquid sourcemisted chemical deposition (LSMCD) method. This method can readily forma micron or sub micron size micro droplet.

A transparent or semitransparent material that can carry out thefunction as a lens after being hardened is sufficient as a material forforming a microlens, and particular restriction is not imposed.Specifically, a material for forming a microlens is suitably selectedfor applications, and, for example, inorganic glass such as soda limeglass, borosilicate glass, and silica glass; resin such as polyethyleneterephthalate, polycarbonate, and polyacrylate; metal oxides such as ZnOand TiO₂; and metal nitrides such as Si₃N are used. Mixtures ofpolymerizable monomers and polymerization initiators may also be used.In addition, a material of a transparent electrode and a materialconstituting an organic compound layer, which will be described below,may be used.

A liquid containing the above mentioned material in a state ofdispersion or dissolution is also sufficient as a liquid containing amaterial for forming a microlens, and particular restriction is notimposed. However, the liquid that has a low affinity to a surface of thesubstrate 101 is preferable. The affinity of the liquid to the substrate101 is relative and varies in accordance with the type of the substrate101. As an index of the affinity of the liquid, which is notparticularly restricted, for example, when an organic solvent is used asa solvent, a contact angle to the substrate 101 is preferably equal to50° or more, more preferably equal to 60° or more, and furtherpreferably equal to 70° or more. Such contact angles tend to enable theformation of a microlens having a higher focal performance.

The material quality of the substrate 101 is not particularlyrestricted, and is suitably selected for applications. If the substrate101 is lyophobic, the range for selecting a liquid that can be usedextends.

The shape of a microlens 103 (or the microlens precursor 102) can beadjusted by suitably controlling the concentration of a liquid, thedegree of an affinity (a contact angle) between the liquid and thesubstrate 101, and the like.

The microlens precursor formed as described above is hardened as shownin FIG. 1B. Thus, a plurality of convex microlenses can be obtained at atime. A method for hardening is not particularly restricted, andhardening process is suitably performed according to the material used.

Additionally, the forms and the sizes of the plurality of formedmicrolenses may be either uniform or nonuniform as shown in FIGS. 2A and2B.

In the case of the substrate 101 made of a lyophilic material, when aliquid is sprayed, the attached liquid to the substrate 101 is spread onthe substrate 101, and therefore the form of a microlens may be notcompleted. In such a case, a lyophobic film may be formed as a substratefilm 105 for forming a microlens.

FIGS. 3A, 3B, and 3C are views for illustrating another example of themanufacturing method of a microlens of the present exemplary embodiment.

The substrate film 105 is formed on the substrate 101 shown in FIG. 3A(refer to FIG. 3B).

The substrate film 105 has a function for controlling the affinity to aliquid, and therefore the shape of a microlens can be adjusted bysuitably changing a material quality of the substrate film 105. Thematerial for forming such the substrate film 105 is not particularlyrestricted, and is suitably selected according to the shape and thematerial quality of a microlens, a contact angle to a liquid,applications, and the like. Thus, a material having a lower affinity tothe material for forming a microlens, namely a material that is morelyophobic (having a larger contact angle to the liquid), than thesubstrate 101 may be used. As a result, a microlens having a higheraspect ratio (the ratio of a height (H) to a length of the bottom (L) islarge) can be formed in comparison with the formation of a microlensdirectly on the substrate 101. As an index of the affinity to theliquid, which is not particularly restricted, for example, when anorganic solvent is used as a solvent of a liquid containing a microlensformation material, a material having the contact angle preferably equalto 50° or more, more preferably equal to 60° or more, and furtherpreferably equal to 70° or more, is preferred. Thus, there is a tendencythat a microlens having a higher focal performance can be formed. Suchmaterials specifically include resin with lyophobicity such asfluorocarbon polymers and polyolefins. From the viewpoint of excellentstability and smoothness, and the like, of the substrate film 105, theuse of a self-assembled monolayer is preferable. Such lyophobicself-assembled monolayer include, for example, flouroalkylsilane (FAS).The self-assembled monolayer can be readily formed by known techniquessuch as applying a liquid containing a material of a self-assembledmonolayer.

As shown in FIG. 3C, a liquid is sprayed and deposited onto a surface ofthe substrate film 105 by the same method as described above, andtherefore the plurality of microlens precursors 102 is formed. Byhardening the plurality of formed microlens precursors 102, theplurality of microlenses 103 is obtained.

Thus, the provision of the substrate film 105 enables a microlens to beformed regardless of the material quality of the substrate 101. By thisprovision, the shape of a microlens can also be readily adjusted.

Regions with different affinities, namely a region with a high affinity(a lyophilic region) and a region with a low affinity (a lyophobicregion), may be formed on the substrate 101.

FIGS. 4A, 4B, and 4C show views for illustrating the method formanufacturing a microlens when regions with different affinities arecreated.

The patterned lyophobic substrate film 105 is formed on the substrate101 shown in FIG. 4A. After the lyophobic substrate film 105 is formedover the substrate 101 having good wettability, for example, part of thesubstrate film 105 is removed by light, such as an electron beam (EB) orvacuum ultra violet (VUV) light or a laser beam, such that the substratefilm 105 having a desired pattern can be obtained. A lyophilic region109 and a lyophobic region 111 can therefore be formed on a surface ofthe substrate 101 (refer to FIG. 4B).

A liquid containing a microlens formation material is then sprayed ontothe substrate film 105 on which the desired pattern is formed. Themicrolens 103 can therefore be selectively formed in the lyophilicregion 109, as shown in FIG. 4B.

According to this example, by suitably adjusting a pattern of thesubstrate film 105, a microlens can be formed in a desired position withexcellent accuracy. By altering the size and the form of the lyophilicregion 109, the size and the form of a microlens can also be adjusted.

Next, a further aspect of the method for manufacturing a microlens ofthe exemplary embodiments will be described.

FIGS. 5A, 5B, 5C, and 5D are views for illustrating another example ofthe manufacturing method of a microlens of the exemplary embodiments.

In this example, instead of forming a microlens by spraying, an etchingprotective film is formed.

The substrate film 105 is formed on the substrate 101 shown in FIG. 5Ain the same way as the above (FIG. 5B). As shown in FIG. 5C, a liquidthat contains a material for forming an etching protective film and hasa low affinity to a surface of the substrate 101 is sprayed, deposited,and hardened onto the substrate film 105.

The material for forming an etching protective film in this case issuitably selected in accordance with the material quality of thesubstrate 101, the method of etching, the type of a etchant, and thelike.

Thus, the shape of an etching protective film can be transferred ontothe substrate 101 as shown in FIG. 5D. The substrate 101 on which themicrolens 103 is integrally formed can thereby be obtained. As a result,in comparison with the formation of the microlens 103 that is made of adifferent material from the substrate, the optical loss can be reduced.

Method for Manufacturing Organic Electroluminescence Element

An example of the method for manufacturing an organic EL element of theexemplary embodiments will now be described with reference to thedrawings.

FIGS. 6A to 6D and 7A to 7D are views for illustrating an example of themethod for manufacturing an organic EL element of the presentembodiment.

As shown in FIG. 6A, a transparent electrode (a first electrode) 303 asan anode is formed on a surface of a substrate (a base material) 301 by,for example, a sputtering method.

Although the material of the substrate 301 is not particularlyrestricted in this case, a transparent substrate made of glass, resin,or the like, is used when the substrate is used as a light-extractionsurface (a light exit surface). Silica glass, blue glass, borate glass,silicate glass, phosphate glass, phosphosilicate glass, borosilicateglass, etc., can be used as glass. Polyethylene, terephthalate,polycarbonate, polyethersulfone, polyarylate, polymethacrylate,polyacrylate, polystyrene, etc., are used as resin.

Before forming the transparent electrode, surface treatment, especiallyby polishing, etc., may be performed to a surface of the base material.Thus, the surface of the transparent electrode can be smoothed. As aresult, shortening the distance between electrodes and occurrence of ashort circuit, which are caused by the unevenness of the surface, can beavoided.

Metal, alloys, conductive compounds, and their mixtures that have largework functions and can provide a desired transparent electrode (atransparent electrode film) can be used as materials for forming atransparent electrode used in the present exemplary embodiment.Specifically, metal such as Au, Ag, and Al having the thickness thatdoes not damage the transparency and dielectric transparent materialssuch as Indium-Tin-Oxide (ITO), SnO₂, and ZnO can be suitably used. Thethickness of the transparent electrode, which is not particularlyrestricted, is, for example, about 100 nm to 200 nm.

As shown in FIG. 6B, a dielectric film is formed of silicon nitride,etc., by deposition, etc., and then a portion corresponding to a pixelregion is removed by etching, etc., thereby forming a bank 305 made ofthe dielectric film.

As shown in FIG. 6C, a substrate film 307 is formed on a portion of thetransparent electrode 303 that corresponds to a pixel formation regionmutually separated by the bank 305.

As this substrate film 307, a film having an affinity to a materialliquid of a microlens, to be formed in the later step (a liquidcontaining a microlens formation material), lower than that of thetransparent electrode 303 (more lyophobic), is preferred. A materialthat has the contact angle to the material liquid of the microlenspreferably equal to 50° or more, more preferably equal to 60° or more,and further preferably equal to 70° or more, is preferred. Such amaterial tends to enable the formation of a microlens having a higherfocal performance. The substrate film 307 preferably has a materialand/or a film thickness that does not interrupt conductivity betweenelectrodes (between the transparent electrode 303 and a cathode 317).Although the thickness of the substrate film 307 differs with thematerial, or the like, and is therefore not restricted, it is, forexample, about 1 nm to 20 nm. A material used for the substrate film 307specifically includes lyophobic resin such as fluorocarbon polymers, andpolyolefins. From the viewpoint of excellent stability and smoothness ofthe substrate film 307, the use of a lyophobic self-assembled monolayersuch as flouroalkylsilane is preferable.

The method for forming the substrate film 307 differs with the materialused and is therefore not particularly restricted. Specifically, acoating method, a spraying method, or a sputtering method, for example,can be used suitably according to conditions.

As shown in FIG. 6D, a microlens 309 is formed on the substrate film 307by spraying and hardening a liquid that contains a material for forminga microlens.

Spraying a liquid so as to produce a particle having an average diameterequal to or less than 1 μm, and preferably equal to or less than 0.5 μm,is specifically preferred. The minute microlens 309 having an averagediameter equal to or less than 5 μm, and preferably equal to or lessthan 1 μm can thereby be formed. Such a spraying method specificallyincludes, for example, a LSMCD method. This method can readily form amicron and sub micron size micro droplet.

A transparent or semitransparent material that can carry out thefunction as a lens after being hardened is preferable as a microlensformation material. Specifically, a transparent or semitransparentmaterial that has, for example, conductivity is used. As an example ofsuch a material, the same material (e.g. ITO) as that constituting thetransparent electrode 303 is preferably used. If the microlens 309 isformed on the glass substrate 301, or the like as described below, theconductivity is not required for the material.

As shown in FIG. 7A, a hole transfer layer 311 is formed by deposition,or the like.

Materials for forming the hole transfer layer 311 (hole transfermaterials) include, for example, triazole derivatives, oxadiazolederivatives, imidazole derivatives, polyarylalkane derivatives,pyrazoline derivatives, pyrazolone derivatives, phenylenediaminederivatives, arylamine derivatives, amino-substituted chalconederivatives, oxazole derivatives, styrylanthracene derivatives,fluorenone derivatives, hydrazone derivatives, stilbene derivatives,silazane derivatives, polysilane compounds, aniline copolymers, andspecific conducting polymer oligomers such as thiophene oligomers, andthe like.

As shown in FIG. 7B, an organic luminescent layer 313 is further formedon the hole transfer layer 311 by deposition, an ink-jet method, or thelike.

Materials for forming the organic luminescent layer 313 (organicluminescent materials) include, for example, benzothiazole,benzimidazole, and benzoxazole fluorescent brighteners; metal chelatedoxinoid compounds; styrylbenzene compounds; distyrylpyrazinederivatives; aromatic dimethylidine compounds; and the like. Althoughthe organic luminescent layer 313 is formed of only an organicluminescent material, it may be formed of a mixture between an organicluminescent material and a hole transfer material and/or an electroninjection material. Specific examples of a material of the organicluminescent layer 313 in this case are molecularly doped polymers whereorganic luminescent materials such as coumarin are dispersed in polymerssuch as polymethyl methacrylate, bisphenol A, polycarbonate (PC), etc.;polymer family where distyrylbenzene derivatives are introduced inpolycarbonate skeletons; or the family where oxadiazole derivatives ofelectron injection properties are dispersed in conjugated polymers suchas polyphenylenevinyl (PPV) derivative family, polyalkylthiophene (PAT)derivative family, polyalkylfluorene (PAF) derivative family,polyphenylene (PP) derivative family, and polyarylene (PA) derivativefamily, or in polyvinylcarbazole of hole transfer properties.

As shown in FIG. 7C, an electron injection layer 315 is formed on theorganic luminescent layer 313 by deposition.

Materials of the electron injection layer 315 (electron injectionmaterials) include, for example, nitro-substituted fluorenonederivatives, anthraquinodimethane derivatives, diphenylquinonederivatives, thiopyranedioxide derivatives, heterocyclic tetracarboxylicacid anhydrides such as naphthaleneperylene, carbodiimides,fluorenilidenemethane derivatives, anthrone derivatives, oxadiazolederivatives, 8-quinolinol derivatives, and other electron transfercompounds.

As shown in FIG. 7D, the cathode layer (cathode) 317 is formed on theelectron injection layer 315 by deposition or a sputtering method, andas a result, an organic EL element is obtained.

Metal, alloys, conductive compounds, and their mixtures that have smallwork functions can be used as materials for the cathode layer 317.Specifically, natrium, magnesium, lithium, alloys or mixed metal ofmagnesium and silver, indium, rare earth metal, and the like can be usedsuitably.

According to the method for manufacturing an organic EL element of thepresent exemplary embodiment, a material liquid (a microlens formationmaterial) with micro particle size that has been atomized as describedabove is deposited onto a lyophobic base material, thereby readilyforming a minute microlens. Providing such a minute microlens betweenlayers of an organic EL element can reduce the optical loss caused by arefractive index difference between layers of the organic EL element,without a need for accuracy of position of the microlens, compared withthe formation of a microlens in correspondence to each organic ELelement.

Although the microlens 309 is formed on the substrate film 307 in theabove described example, the microlens 309 may be formed without the useof the substrate film 307 when an affinity between the transparentelectrode 303 itself and the material liquid is low. The microlens 309may also be formed by the use of patterning of the substrate film 307and formation of a lyophilic region as well as a lyophobic region. Inthis case, in order to reduce the optical loss between the microlens 309and the transparent electrode 303 that is the lower layer, it ispreferable that the refractive index difference between the microlensformation material and the transparent electrode 303 be equal to or lessthan 0.05, and more preferably equal to or less than 0.02. Moreover, itis preferable that the refractive indices of a microlens formationmaterial and a material constituting the transparent electrode 303 besubstantially equal. When a microlens is formed on a glass substrate,the microlens may be formed by the use of etching of the glasssubstrate, as described above.

In the above described example, the microlens 309 is formed between thetransparent electrode 303 and the hole transfer layer 311, but this isnot restrictive. As shown in FIGS. 8A and 8B, the microlens 309 may beformed between any layers from the organic luminescent layer 313 to alight exit surface 330 or on the light exit surface 330.

In the above described example, description is also given using aninstance of stacking each layer on the substrate 301 at thelight-extraction surface side (the light exit surface side). Theformation of a microlens is not restricted to this instance; when eachlayer is stacked on the substrate at the opposite side to thelight-extraction surface, a microlens can also be formed between thelayers constituting the organic EL element in the same way as in thisinstance. The substrate in this case may be a semitransparent ortransparent substrate. A transistor for driving the organic EL elementand other units may be formed in the substrate.

The layer construction of an organic EL element is also not particularlyrestricted to the above described example, and may be, for example, thefollowing (1) to (8). In the following (1) to (8), the layerconstructions are described in the order of stacking layers on asubstrate.

-   -   (1) Anode (transparent electrode)/hole transfer layer/organic        luminescent layer/electron injection layer/cathode (mirror        surface electrode);    -   (2) Anode (transparent electrode)/hole transfer layer/organic        luminescent layer/cathode (mirror surface electrode);    -   (3) Anode (transparent electrode)/organic luminescent        layer/electron injection layer/cathode (mirror surface        electrode);    -   (4) Anode (transparent electrode)/hole transfer layer/organic        luminescent layer/adhesive layer/cathode (mirror surface        electrode);    -   (5) Anode (transparent electrode)/organic luminescent        layer/cathode (mirror surface electrode);    -   (6) Anode (transparent electrode)/mixed layer of hole transfer        material, organic luminescent material, and electron injection        material/cathode (mirror surface electrode);    -   (7) Anode (transparent electrode)/mixed layer of hole transfer        material and organic luminescent material/cathode (mirror        surface electrode); and    -   (8) Anode (transparent electrode)/mixed layer of organic        luminescent material and electron injection material/cathode        (mirror surface electrode).

In addition to the above layers, a hole injection layer, an electrontransfer layer, and other layers may be included as necessary. Materialsused for such layers are not particularly restricted.

Electro-Optic Device and Electronic Equipment

The method for manufacturing a microlens and the method formanufacturing an organic EL element of the exemplary embodiments can bepreferably utilized for a method for manufacturing electro-optic devicesand electronic equipment. That is, by utilizing the above describedmanufacturing method of an organic EL element (organic thin filmelement) for a manufacturing method of electro-optic devices andelectronic equipment, long lifetime electro-optic devices and electronicequipment can be provided by the use of simple steps.

The electro-optic devices in this case are the devices that utilize theelectro-optic effect, and include, for example, organic EL displaydevices.

FIG. 9 shows an example of the organic EL devices. As shown in FIG. 9,an organic EL device can be formed, for example, by combining an organicEL element 300 manufactured as described above with a substrate(hereinafter, TFT substrate) 200 on which a thin film transistor isformed. Note that the TFT substrate 200 mainly includes a semiconductorfilm 213, a dielectric film 203, a gate electrode 209, an interlayerdielectric film 205, metal wiring 211, a protective film 207, and apixel electrode 215 on a substrate 201 made of glass or the like.

The number of the organic EL elements 300, which constitute the organicEL device, may be one or may be more than one. When the plurality oforganic EL elements 300 is placed, the luminous colors of the organic ELelements 300 may be the same or may be different from one another. Theorganic EL elements 300 of single type or a plurality of types areformed in a desired shape such that the organic EL device as a whole hasa desired luminous color. For example, in order to create a whiteluminous color of the organic EL device as a whole, the organic ELelement 300 that emits red light, an organic EL element that emits greenlight, and an organic EL element that emits blue light are located instripe shape, mosaic shape, triangle shape, four pixel location shape,or the like. The luminous color of the individual organic EL element 300varies according to the type of the organic luminescent material, andtherefore the type of the organic luminescent material to be used issuitably selected such that the organic EL device as a whole has adesired luminous color.

Although the above described example illustrates a top emission typeorganic EL display device, an organic EL display device is notrestricted to this example and may be a bottom emission type organic ELdisplay device.

Although the above described organic EL element is formed on thesubstrate, one or double protective layers for preventing the organic ELelement from invading moisture may be placed so as to cover the organicEL element formed on the substrate since an organic EL element isgenerally vulnerable to moisture.

Such organic EL display devices can be used for various types ofelectronic equipment. FIGS. 10A to 10D and FIGS. 11A and 11B are viewsshowing examples of various types of electronic equipment that includeelectro-optic devices 600 (such as organic EL display devices).

FIG. 10A is an example of the application to a cellular phone. Acellular phone 830 includes an antenna 831, a sound output section 832,a sound input section 833, an operation section 834, and theelectro-optic device 600 of the invention. FIG. 10B is an example of theapplication to a video camera. A video camera 840 includes a picturesection 841, an operation section 842, a sound input section 843, andthe electro-optic device 600. FIG. 10C is an example of the applicationto a portable type personal computer (so-called PDA). A computer 850includes a camera section 851, an operation section 852, and theelectro-optic device 600. FIG. 10D is an example of the application to ahead mount display. A head mount display 860 includes a band 861, anoptical system storage section 862, and the electro-optic device 600.

FIG. 11A is an example of the application to a television set. Atelevision set 900 includes the electro-optic device 600. Theelectro-optic device 600 can also be applied to a monitoring device usedfor a personal computer or the like. FIG. 11B is an example of theapplication to a roll-up type television set. A roll-up type televisionset 910 includes the electro-optic device 600.

The above described examples illustrate organic EL display devices asinstances of electro-optic devices, but electro-optic devices to whichthe methods of the exemplary embodiments are applied are not restrictedto these examples. The methods of the exemplary embodiments can beapplied to manufacturing methods of electro-optic devices that use othervarious types electro-optic elements (such as plasma light-emittingelements, electrophoretic elements, and liquid crystal elements).Electro-optic devices are not restricted to the above describedexamples, and can be utilized for electronic equipment such as a surfaceilluminant, a liquid crystal display device or a pack light of a watch,a character display device, a device for electric spectaculars, anindicator for automobile use, a light source for a eliminator of acopying machine, a light source for a printer, and an optical modulationdevice.

EXAMPLES Example 1

An indium-tin-oxide (ITO) film as an anode formed on a transparent glasssubstrate of 25×75×1.1 mm by a sputtering method was prepared as a basematerial. At that time, the average surface roughness Ra aftersputtering was 7.33 nm. A solution containing flouroalkylsilane (FAS)was then applied onto the ITO film such that a substrate film havinglyophobicity was formed. A liquid containing a microlens formationmaterial (a material liquid) was deposited onto the substrate film by aLSMCD method such that microlens precursors were formed. At that time,ITO was used as a microlens formation material in the same way as informing the anode, and butyl acetate was used as a solvent. Then themicrolens precursors were dried and annealed, and as a result, themicrolenses were obtained. Because FAS did not evenly spread in a wetstate on a surface due to its low affinity to the material liquid,convex lens shaped minute microlenses could be formed. Although thesurface of the ITO film after sputtering did not have excellentsmoothness, forming the microlenses by a LSMCD method caused improvementof the smoothness.

FIG. 12 shows an electron micrograph of the obtained microlens.

A hole transfer layer, an organic luminescent layer, and a cathode wereformed one atop another on a microlens layer, and as a result, anorganic EL element was obtained. The method for forming the holetransfer layer, the organic luminescent layer, and the cathode will bedescribed below.

The glass substrate on which the ITO film was formed as described abovewas fixed to a substrate holder of a vacuum deposition device, 200 mg ofN,N′-diphenyl-N,N′-bis(3-methylphenyl)-(1,1′-biphenyl)-4,4′-diamine(hereinafter, TPD) was put into a resistance heating boat made ofmolybdenum and 200 mg of tris(8-quinoline)aluminum (hereinafter, Alq)was put into another resistance heating boat made of molybdenum, and theinside of a vacuum chamber was depressurized to 1×10⁻⁴ Pa.

Then, the resistance heating boat in the first stage in which the TPDwas put was heated to 215 to 220° C., and the TPD was deposited onto theITO film with a deposition speed of 0.1 to 0.3 nm/sec, forming a holetransfer layer with a film thickness of 60 nm. The substrate temperatureat that time was set at room temperature. Then, without taking thesubstrate on which the hole transfer layer was formed out of a vacuumchamber, the formation of an organic luminescent layer was subsequentlyperformed. As for the formation of the organic luminescent layer, theresistance heating boat in which the Alq was put was heated to 275° C.,and the Alq was deposited with a depositing speed of 0.1 to 0.2 nm/seconto the hole transfer layer, forming an Alq layer with a film thicknessof 50 nm. The substrate temperature at that time was also set at roomtemperature. Then 1 g of magnesium was put into a resistance heatingboat made of molybdenum, 500 mg of indium was put into anotherresistance heating boat made of molybdenum, and the inside of a vacuumchamber was depressurized to 2×10⁻⁴ Pa. The resistance heating boat madeof molybdenum in which the magnesium was put was heated to about 500°C., and the magnesium was deposited with a deposition speed of about 1.7to 2.8 nm/sec, while the resistance heating boat made of molybdenum inwhich the indium was put was heated to about 800° C., and the indium wasdeposited with a deposition speed of about 0.03 to 0.08 nm/sec. Thus, acathode (a mirror surface electrode) made of mixed metal of magnesiumand indium with a film thickness of 150 nm was formed on the organicluminescent layer. As a result, an organic EL element that includes theanode (ITO film), the hole transfer layer, the organic luminescentlayer, and the cathode formed one atop another on the substrate wasobtained.

Example 2

A solution containing flouroalkylsilane (FAS) was applied onto atransparent glass substrate of 25×75×1.1 mm prepared as a base materialsuch that a substrate film having lyophobicity was formed. A liquidcontaining a microlens formation material (a material liquid) was thendeposited onto the substrate film by a LSMCD method, and thereforemicrolens precursors were formed. At that time, a dispersion liquid inwhich SiO₂ was dispersed in butyl acetate was used as the microlensformation material. Then, the microlens precursors were dried andannealed, and therefore microlenses were obtained. Since FAS did notevenly spread in a wet state on a surface due to its low affinity to thematerial liquid, convex lens shaped minute microlenses could be formed.Then a material liquid containing ITO was deposited onto a microlensarray layer by a LSMCD method, and then dried and annealed, and thus atransparent electrode as an anode was obtained. Forming the ITO film bya LSMCD method enabled formation of the ITO film having a smoothsurface.

Then, a hole transfer layer, an organic luminescent layer, and a cathodewere formed one atop another on the microlens layer, and as a result, anorganic EL element was obtained.

Example 3

A solution containing flouroalkylsilane (FAS) was applied onto atransparent glass substrate of 25×75×1.1 mm prepared as a base materialsuch that a substrate film having lyophobicity was formed. A liquidcontaining an etching protective film formation material (a materialliquid) was then deposited onto the substrate film by a LSMCD method,and thus an etching protective film having the shape of a plurality ofconvex lenses was formed. At that time, ITO was used as the etchingprotective film formation material. Then the pattern of an etchingprotective film was transferred to the glass substrate, and thereforethe glass substrate on which microlenses were integrally formed wasobtained. Then a material liquid containing ITO was deposited onto amicrolens array layer by a LSMCD method and then dried and annealed, andthus a transparent electrode as an anode was obtained. Forming the ITOfilm by a LSMCD method enabled formation of the ITO film having a smoothsurface.

Then, a hole transfer layer, an organic luminescent layer, and a cathodewere formed one atop another on the microlens layer, and as a result, anorganic EL element was obtained.

Example 4

A solution containing flouroalkylsilane (FAS) was applied onto atransparent glass substrate of 25×75×1.1 mm prepared as a base materialsuch that a substrate film having lyophobicity was formed. The substratefilm was then exposed to VUV light using a mask and patterned such thata lyophilic region and a lyophobic region were formed. A material liquidin which SiO₂ was dispersed in butyl acetate was then deposited onto thepatterned substrate film by a LSMCD method. In depositing, SiO₂ wasselectively deposited in the lyophilic region. The substrate film wasthen dried and annealed, and thus microlenses were obtained. Then, amaterial liquid containing ITO was deposited onto this microlens layerby a LSMCD method and then dried and annealed, and thus a transparentelectrode as an anode was obtained. Forming the ITO film by a LSMCDmethod enabled formation of the ITO film having a smooth surface.

Then, a hole transfer layer, an organic luminescent layer, and a cathodewere formed one atop another on the microlens layer, and as a result, anorganic EL element was obtained.

In this example, since SiO₂ is formed in accordance with the pattern ofthe lyophilic region and the lyophobic region, the surface shape can bereadily adjusted.

1. A method for manufacturing an organic electroluminescence element,the method comprising: forming a first electrode on a substrate; forminga bank on the substrate so that the bank overlaps with a first part ofthe first electrode; forming a substrate film on a second part of thefirst electrode with which the bank does not overlap, the substrate filmincluding a polyolefin having a thickness between 1 to 20 nm; spraying aplurality of droplets to attach the plurality of droplets on thesubstrate film, each of the plurality of droplets having transparencycharacteristics, a contact angle between each of the plurality ofdroplets and the substrate film being more than 50 °; hardening theplurality of the droplets attached on the substrate film to form aplurality of microlenses on the substrate film, each of the plurality ofmicrolenses and the first electrode including a same conductivematerial; forming an organic electroluminescence film on the pluralityof microlenses; and forming a second electrode on the organicelectroluminescence film, electrons being transferred between the firstand second electrodes and passing the substrate film.
 2. The method formanufacturing an organic electroluminescence element according to claim1, a refractive index difference between a material for forming themicrolens and a material comprising a layer on which the microlens isformed being equal to or less than 0.05.
 3. The method for manufacturingan organic electroluminescence element according to claim 1, arefractive index of each of the plurality of microlenses and arefractive index of the first electrode being substantially equal. 4.The method for manufacturing an organic electroluminescence elementaccording to claim 1, the plurality of microlenses being configured tocollect a light emitted from the organic electroluminescence film. 5.The method for manufacturing an organic electroluminescence elementaccording to claim 1, the plurality of microlenses being configured tocollect a light emitted from the organic electroluminescence film and toemit the collected light to the substrate.
 6. The method ofmanufacturing an organic electroluminescence element according to claim1, the plurality of droplets being sprayed by a liquid source mistedchemical deposition method.